Jet size differences

[jdub6092]

My 81 gs650e BS32 carb lists the following standard jet sizes vs. those that I have installed:
Main jet - 97.5 -> 110
Pilot jet - 42.5 -> 42.5
Pilot air jet - 175 -> 160
I purchased a K& L kit, but if it will make a difference I will purchase some Mikuni jets. Where is the best store to purchase them?
What differences might I notice with my current arrangement? I see more fuel passing through the main and less air into the pilot jet.

[KiwiAlfa156]

What is the purpose of making changes? Are you jetting to correct for intake or exhaust changes/modifications?

[jdub6092]

No mods, had to replace a few when I first tore them down for cleaning. The 110s and 160s were what
was in the K&L kit.
I see that these were common on other 650 models.

[Nessism]

I'd put the jetting back to stock. You can get proper Mikuni main jets at hundreds of sources, air jets, though, are going to be tough to find. The parts diagram suggest 175 is the proper size for the air jets. Did you save the originals?

[dubwicht]

The only way to really know how the jets/exhaust/air filters etc. are affecting the bike is to use the spark plug test. Buy 2 sets of plugs and a plug cleaner. Clean the plugs and run the bike on idle for 5 minutes. Remove the plugs and note the color. Golden brown on the center ceramic is ideal. No color means too lean. Black means rich. Adjust with the idle screws or change jets. Make sure the bike is warmed up and replace the plugs with clean ones. Start the bike and quickly get up to middle speed or about 80% of max. Shut off the bike, pull over and check the plugs using the same test used for in idle. Adjust by raising or lowering the needles. Put in another clean set in and quickly accelerate to the top 20% of speed. Again, shut off the bike and pull over. Inspect the color and adjust by changing the main jet size. You can also do this with a dyno tune machine if you have access to one.

Prior to doing these tests make sure that the timing is spot on and that valves are adjusted according to the service manual. Also make sure that the carbs are clean, synced and operating properly. These tests are the final tuning. This seems like allot of work but it is the only way to make sure that the bike is running at it peak.